I think you need to plan your cities more like a small country town, and expect less density per meter of road than the game actually lets you put down. Rather than playing to the games metrics of population and income, just expect less of the city and spread it out more.
Every time I come back to it I have another dig through the menus, thinking I must be missing something, but there’s no “car-free city” option. As far as I understand, the new Plazas & Promenades DLC does not actually address this either.
Am I missing something? Why does the end-game always have to be traffic? Seems like a wasted opportunity.
You can avoid having to spend too much time on managing traffic if you follow some "design patterns", there is a bunch of them, so Google is probably your best friend.
Although, there is a good comment on reddit that gives a quick overview, with links to more in-depth material, that might be a good starting point for you: https://old.reddit.com/r/CitiesSkylines/comments/m57lq8/how_...
The other strategy is getting everyone onto bikes and onto public transport. If they can do it, citizens will prioritize public transport and cycling over cars. So once you get rid of the trucks, and design the city in such a way that citizens can cycle/train to work/commercial then you'll reduce heaps of traffic.
Interestingly, I built high speed rail to a second town I built that's only connection is the railway, it's quite small but also very little traffic. Almost everyone takes the rail into the main city for work. I think better cities in the game would actually be to treat suburbs like a series of small towns, rather than lots of massive city blocks.
